


Twins Don't Need to Have Logic

by Anti_Social_Headphones_Kid



Category: Rise of the Teenage Mutant Ninja Turtles (Cartoon 2018)
Genre: Disaster Twins, Donnie-centric, Gen, I seriously suck at summeries, I'm also obsessed with it, Lol sorry for this, No one gets hurt, One-Shot, and I just wanted to have a go at it, cuz even tho there's already a bunch, family love, low-key feels with a happy ending, not t/cest, pleASE get away from this t/cest's, that whole twin trope thing that the rise fandom likes, there's some fighting but they love each other
Language: English
Status: Completed
Published: 2020-02-15
Updated: 2020-02-15
Packaged: 2021-02-27 19:09:02
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,642
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22730758
Author URL: https://archiveofourown.org/users/Anti_Social_Headphones_Kid/pseuds/Anti_Social_Headphones_Kid
Summary: Leo stopped calling them 'twins' years ago and thought Donnie would've been grateful for that...Little does he know how his brother actually feels
Relationships: Donatello & Leonardo (TMNT)
Comments: 22
Kudos: 451
Collections: Read or Be Jared 19 Pick Your Poison





	Twins Don't Need to Have Logic

**Author's Note:**

> Me? Writing a one-shot instead of working on my several other WIP??  
> It’s more likely than you think
> 
> Ahhhhh sorry for doing the whole ‘twin trope’ I know there’s a bunch of amazing ones already out there, but I really wanted to try it out too lol- I hope you enjoy!
> 
> (btw don’t freakin touch this t/cest’s, not even with a ten-foot pole)

_Seven years ago:_

“Come on Donnie! Let’s just try it!” Leo said excitedly, bouncing around Donnie as he tried to fix the microwave- it had broken recently, and this was the first thing that Splinter had entrusted him to fix. It was a pretty big deal, and even though he was sure he could manage it, having Leo moving around him was distracting and annoying.

He glanced at where Raph was, hoping that his older brother would notice his annoyance and get Leo to leave him alone, but he was currently reading to Mikey and hadn’t noticed the situation.

Maybe it wouldn’t have even been as annoying had Leo been talking about something actually reasonable for once- but no, instead he was just going on about them being ‘twins’. 

Again.

He was used to humouring Leo's idea for now, though he was convinced that Leo would eventually realize the stupidity of it all and accept the truth- but every time Donnie had tried to explain that they weren’t twins, Leo would just say that none of it mattered and that they would always be twins no matter what.

And now Leo was convinced that they might have ‘twin telepathy’.

Great. Instead of outgrowing this faze, he seemed content on continuing to disillusion himself with this annoying fantasy.

But he didn’t feel like going into it right now, so instead he opted to ignore Leo and focus on the microwave.

"Leo, I told you, it's impossible to have a 'connection,'" Donnie stated for what felt like the hundredth time, his eyes still glued to his project.

“Hmmm, try reading my thoughts Don! Then we can know for sure!”

“No, Leo, I’m trying to work,” he responded quietly.

“Does it work if we get hurt too?" Leo wondered aloud, still refusing to drop the subject. "Like can you feel if I get hurt?”

“No.”

Leo looked at Donnie, finally noticing his concentration was focused on the microwave, and stopped moving around- instead he sat down across from where Donnie was and looked at him eagerly.

“Do you want some help with that?”

Donnie sighed. “Thanks Leo, but no, I got it. I don’t think you’d be able to help, this is some pretty complicated stuff,” he said with slight pride.

“Oh, ok… but what if you just sent me what to do through your mind?” Leo suggested excitedly.

“What?”

“With our twin-telepathy!”

“Leo, I’ve already told you. We aren’t twins,” he stated firmly.

Donnie ignored the feeling of Leo staring at him and kept his focus on the machine in front of him, even if his attention had started to go more on his so-called ‘twin’.

“Why not?” Leo finally asked.

“Why what?”

“Why aren’t we twins?”

“Leo, we aren’t even the same species of turtle-”

“So? What does that have to do with it?”

“It has everything to do with it,” Donnie snapped, finally looking up to face Leo. 

“We’re the same age though, and-”

“Being the same age means nothing- if it did, then literally everyone our age would be considered a ‘twin’- do you realize how stupid you sound?”

“But we’re the same age and we’re brothers!” Leo argued.

“We’re hardly even brothers- any of us- much less twins. Now I need to finish this, so leave me alone,” he stated before looking down again and working on the microwave.

He saw out of the corner of his eye as Leo got up and left without another word, leaving a tiny feeling of accomplishment in Donnie. Maybe now Leo would finally drop this whole thing.

Donnie felt Raph and Mikey staring at him, but he ignored it and kept on working- they didn’t know what it felt like to have someone obsessively try to convince you that you’re something you aren’t. Then again, he was pretty sure Raph would be ok with pretending, and Mikey had probably believed that he and Leo were twins… but whatever, it didn’t matter, it was done with.

“It was the truth,” Donnie defended, turning to face Raph, suddenly filled with the need to explain himself.

“You really hurt Leo though,” Raph said gently.

Donnie shrugged. “Sometimes the truth hurts.”

“Don.”

“What? Did you expect me to keep on entertaining him? To keep telling him lies to keep him happy? Why would I do that? It’s easier to get it done with now, that way he won’t be disappointed later.”

“So… then you don’t think we’re brothers?” Mikey spoke up softly from where he was sitting beside Raph.

“What? No of course we are- I mean, we aren’t related by blood, but we’re still brothers,” he assured the orange-clad turtle. “It’s just, being twins is something entirely different- there’s no way we could physically be-”

“We _know,_ Donnie, you say the same speech almost every day, I’m pretty sure we all have it memorised by now,” Raph stated.

“I haven’t said it that much,” he mumbled, unsure why they weren’t understanding what he was saying.

“You say it every time Leo calls you his twin- we all know the ‘scientific reasons’ why you don’t call him your twin.”

“Then why doesn’t he just accept that we aren’t related already? Then I won’t have to explain it so much.”

“You think he doesn’t understand that you aren’t blood-related? I think he understands it better than you do, but it doesn’t matter to him- he wants to be your twin because he thinks that he’ll never be alone that way. So you’ll never have to be alone. He just wants to be with you Donnie, he doesn’t care about all the specifics of it.”

Donnie looked away from Raph and back at the microwave. It wasn’t his fault for telling Leo the truth… even if Leo had already realized it. If he wanted them to be closer, he could’ve just _said so_ \- but Donnie realized that _had_ been Leo’s way of asking.

_Shoot._ So did it just turn out that he was the stupid one?

Donnie tugged on his hoodie’s sleeves in frustration as he thought to himself, ignoring as Raph said goodnight to him before taking Mikey to get ready for bed, leaving Donnie alone.

He stayed in the same position, staring at the broken pile of pieces in front of him for what felt like hours until he finally decided to get up and make things right.

He walked through the dark tunnels and finally stopped outside Leo’s room. Part of him wondered if Leo would be asleep already since it was pretty late, but the other part of him knew that Leo was wide-awake behind that curtain. 

Huh, maybe he did have a twin-sense or whatever. 

(He automatically hated himself for even thinking that.)

He cleared his throat a bit before pulling back the curtains and stepping in the room where he came face-to-face with Leo who looked up from his DS to where Donnie was standing before quickly returning his gaze to his game.

“What do you want?” Leo asked boredly, his calm voice obviously a mask for his shakey emotions.

“Um, I wanted to apologize…” Donnie started quietly, unsure of what to start with. Probably the apology first, then the explanation, right? “I’m sorry I-”

“No, you don’t have to apologize,” Leo said casually from where he was sitting on his bed.

“What?”

“You don’t need to apologize- you were right, we aren’t twins. I dunno why I was so hung up on it, sorry, I was being stupid.”

_What?_ No, this wasn’t supposed to be how it worked, Leo wasn’t supposed to be the one apologizing, it was supposed to be _him_ , then they would work it all out, and Leo would call them twins again, and this time he wouldn’t argue with him-

“Oh, ok, cool,” Donnie replied against the will of his inner conversations. “So we’re good then?”

“Yeah. We’re good,” Leo confirmed, his eyes not leaving his game.

Donnie turned to leave, his head still buzzing, unsure of what to say. He desperately wanted to turn around and argue that they _were_ twins, but what would Leo say to that? He had just accepted it, and done what Donnie had been asking him to do- he couldn’t tell Leo to forget everything and go back to the way things were, so he simply said “goodnight,” and left.

After that day, Leo never mentioned them being twins again. Every day Donnie waited to hear him mention it- even just once- so he could use it as an opportunity to agree with him, to accept him, but it never came, and eventually, Donnie stopped waiting for it. He realized that Leo would probably never call him that again, so he pushed it out of his mind instead, trying to forget about it.

* * *

_Present-day:_

Donnie was usually pretty good at keeping his lab clean…

Ok, he was _relatively_ good, and Shelldon did most of the cleaning, but still, it was usually in pretty good shape. His closet on the other hand… He hadn’t cleaned that out in an incredibly long time- instead, he often just chose to throw anything and everything he didn’t feel like dealing with inside, and just leave it there to rot, confident that he wouldn’t need whatever-it-was for a long time, but also confident that he could eventually use whatever spare parts he had thrown in there.

This time though, he regretted his former decisions, as he suddenly realized he had a use for the old remote control car he’d thrown in there years ago- and honestly, how hard could it be to find it?

_Whelp_. After three hours of digging through old parts and wires he honestly just should’ve thrown away, he was starting to consider calling it quits. It seemed that the car was gone, lost forever, when he caught sight of it underneath a few boxes.

He took ahold of the car, and lifted the boxes a bit, pulling the car from under them, when one of the boxes on top fell from the pile he was lifting, falling to the ground, opening on impact and scattering its contents all over the floor. 

Donnie groaned at the mess and finally pulled the car out before setting it on his desk and heading back to where the boxes various items had fallen out. He was surprised to see that instead of spare parts like most everything else in his closet, this one had a few old photos mixed in as well.

He picked up a few of them, smiling as he looked at the much younger versions of him and his brothers. It was weird to have actual solid photographs instead of just looking through them on his phone, but it was kind of cool too.

He turned over the photo of them watching a movie together and saw Splinter’s scratchy handwriting stating that it had been taken during their first _Loi Jitsu_ movie.

His task of cleaning up was forgotten, as he started to flip through the photos one by one, turning each to see on which occasion it was taken.

He came across one particularly horrible one of him and Leo, which had apparently been taken by Leo himself- which considering it was a selfie done with an actual camera by a five-year-old, it didn’t turn out all that terrible, but it was still pretty bad.

He turned it over to see what was written on the back, but instead of seeing his father’s familiar handwriting, Donnie was met with the messy scribbles of young Leo (that honestly was slightly better than Leo’s current handwriting), that read: ‘ _happy birthday to my twin!’_

Donnie went still when he saw those words… He’d almost forgotten about that, that Leo used to call him that- it all rushed back to him, what he said, what had happened.

He turned the photo back around in his hand, staring at the two of them in the photo.

After that day, Leo had acted coldly towards him for a while, but eventually, he got over it and went back to normal… he had gone back to normal, right? Or had Donnie just gotten used to Leo acting cold that it _seemed_ normal? No, Leo wouldn’t have held a grudge for so long, but still… would they have been closer if Donnie had just accepted him as a twin? Why hadn’t he just said something to Leo?

What use was it to be thinking about this now? It was pointless.

Donnie found himself pausing, hesitant to put the photo back in the box, so instead, he set it aside and put it in his room beside all his other digital photos- It threw off the vibe a little, but Donnie wanted it there. He wanted that horrible, awful photo on display, and he wanted it to have Leo’s handwriting on the back, calling him his twin.

He didn’t know why he wanted it there, but he did.

* * *

Donnie thought eventually he’d forget about the whole ‘twin thing’ again, but it seemed to stick to his thoughts, always in the back of his mind… and he didn’t hate it. He kinda actually liked the thought of having a ‘twin,’ as stupid as it sounded.

He took out his phone and changed Leo’s contact name to _‘twin’_. It was pointless, but no one would see it, so it was fine.

* * *

Donnie was watching tv with Mikey when they heard a large crash come from somewhere in the lair.

“LEO WHAT DID YOU DO?” Donnie yelled from where he was sitting on the couch, startling Mikey with the sudden loudness.

“DON’T WORRY, NOTHING BROKE,” Leo shouted back from wherever-he-was, earning him an eye roll from Donnie despite not being able to see it.

“How’d you know it was Leo and not Raph?” Mikey asked curiously.

“We’re twins, it’s hard not knowing when he’s doing something stupid,” Donnie replied boredly without looking up from his phone, leaving Mikey in silent shock for over a minute.

“What did you just say?” Mikey finally asked, unsure of himself.

“What?”

“About Leo, you- what did you say?”

“It’s hard not knowing when he’s doing something stupid?” Donnie repeated tiredly.

“No, no before that.”

Donnie’s eyes suddenly widened in realization, before he returned to his normal expression in an attempt to play it off.

“I didn’t say anything before that.”

“Yes, you did- you said- um, nevermind…”

Donnie let out a silent sigh of relief as Mikey turned his attention back to the screen, questioning himself on why he had said that, and why he had actually kind of _liked_ calling Leo that.

* * *

Raph, Mikey, and Donnie were in the kitchen playing Uno as they waited for Leo to get back with the pizza.

In hindsight, he shouldn’t have let his phone leave his person, but he had only left it on the table for one minute, which honestly should’ve been fine.

And it would’ve been fine, had Leo not chosen to call at the exact moment- or well, it would’ve been fine had he called Raph or Mikey, but he had called _him_ , and well…

“Who’s calling?” Donnie asked carelessly when he heard his phone buzz as he grabbed a glass from the cupboard and filled it with water.

“Hm one sec,” Raph replied, reaching across the table and grabbing Donnie’s phone to check. “It’s um…” he paused in confusion before the realization hit him, and he turned to Donnie, still slightly unsure of what he just saw. “I think it’s Leo,” he said finally.

“Then answer it,” Donnie said with slight annoyance, not realizing his own mistake yet.

“R-right, I’ll answer,” Raph affirmed before accepting the phone call and quickly answering Leo’s question on their orders.

Donnie retook his phone from Raph and sat down in his usual spot, still unsure why his older brother was staring at him weirdly.

They played through a few turns before Donnie got slightly annoyed with the stares that he kept receiving.

“Raph, why are you looking at me like that?” he sighed, setting his cards down on the table.

“What? Like what? I’m not doing anything weird.”

“Really? Then is it me?”

“No, no- I just think that maybe Leo changed his name on your phone.”

“Seriously? Again? I thought I finally made it secure,” Donnie said tiredly, taking his phone out and going to Leo’s contact, only to freeze when he came to his twin’s contact and see that it was none other than the name he had put in for his twi-brother, and decidedly _not_ Leo’s doing.

He subtly set his phone back on the table, hoping that neither of them would ask any further questions, but from the way Raph was glancing at him in a concerned manner, he realized that he would have no such luck.

“I wouldn’t be mad at Leo, it was only a joke,” Raph brought up casually.

“I’m not mad at him,” Donnie replied truthfully.

“Oh? That’s good then,” Raph answered, much more relaxed. “I remember how you guys used to be,” he added with a slightly nervous laugh, but Donnie just shrugged, and tried to keep his focus on their game.

He understood Raph was just trying to make sure there wasn’t going to be an argument about it later- which was fair since that was one of their most frequent fighting topics when they were younger- but it felt like a punch when he realized that not only did Raph remember those fights, but he also remembered how angry he used to get at Leo, and in turn how angry Leo would get at him…

“Why? What did he change it to?” Mikey asked, confused with the sudden tenseness that had come over them.

“It’s nothing, just an old joke,” Raph answered, still watching Donnie from the corner of his eye as if he was afraid Donnie was going to suddenly become upset.

Mikey continued to look slightly confused as he glanced between his two older brothers, uncertain of what was happening until the sudden realization hit him.

“You mean like how Leo used to say they were twins?" he asked, still slightly confused.

“Yes Mikey,” Raph replied in a rush before Donnie could get a word in. “But let’s just leave it alone now, ok?”

“But Donnie calls Leo his twin all the time,” Mikey replied, still confused.

“What? No, I don’t.”

“Yeah, you said it while we were watching tv yesterday, and when I was asking you where he was last week, and when I was helping you in the lab, and-”

Donnie felt his heartbeat pick up as his youngest brother continued to list off times he had apparently said it out loud. Why was Mikey even keeping track of this?

“Ok stop! You don’t have to keep going,” Donnie said, recovering from his shock and putting his hand over Mikey’s mouth, who only glared at him in annoyance and removed his older brother's hand. 

The three of them went quiet as Raph and Mikey stared at him while he tried to ignore them and continue on as if the whole conversation hadn’t just happened.

“Donnie-” Raph began carefully.

“Fine- I call Leo my twin, ok? I _know_ it’s stupid, and I don’t know why-” Donnie stopped, unsure of what to say. There wasn't anything he could say in his defense or to deny, and now they were just _staring_ at him. What was he even supposed to say?

“Donnie, it’s ok, we get it- we aren’t judging you… but I just really think you should talk to Leo about this,” Raph finally said gently.

“No, I can't," Donnie replied in frustration. "Just- forget about this, please… and don’t tell Leo.”

Raph and Mikey exchanged concerned glances, but nodded in agreement and returned to their game.

* * *

They were in a battle with Big Mama after they were caught in an attempt to get more of her web-goo stuff, and it wasn't exactly going well- they probably could’ve been better prepared, but then again, they hadn’t been expecting to be caught in the act- it was supposed to be stealth only- but somewhere along the way, their plans had gone awry and now they were engaged in a battle: the four of them vs the hundreds of workers.

Not exactly fair.

Donnie and Leo had been separated from Mikey and Raph at some point, leaving their only communication through their phones.

_“Donnie, Leo, are you guys together?”_ Raph shouted through the phone, trying to be heard throughout the chaos.

“Yes,” Donnie answered shortly while attempting to fight off one of the staff members.

_“Good- if you guys can escape, then just go- Mikey and I will do the same, and we can meet up at our usual spot,”_ Raph instructed.

“Copy that leader,” Leo replied casually as if they weren’t in the middle of a raging battle.

“Leo, can’t you just portal us out of here with your sword?” Donnie asked, blasting one of the workers into three others.

“Not while I’m trying to fight with it- cover me,” he instructed, drawing his attention away from the battle, just as Donnie was knocked down.

“Leo wait!” Donnie yelled, trying to get up as quickly as he could, only to watch one particularly large mutant grab Leo by the neck and begin to choke him.

He felt faint as he saw Leo lifted off the ground. He barely heard as his sword fell from his hand onto the floor.

_Move_ , Donnie instructed himself, but he found himself frozen as the mutant hit his twin in the head unconscious, and dropped him on the floor.

Donnie didn’t know what to do- he knew what he _should_ do, but his mind was reeling and his breaths were shallow as he stared at the limp body of his brother.

He saw the mutant reach again for Leo, and suddenly he was filled with blind rage.

“Stay away from my twin!” Donnie yelled, blasting away the mutant from where Leo was laying on the floor unconscious.

He hoisted his brother’s body up before picking up the sword from the ground and considering asking Raph to come and help-

“Um… what did you just call me?” Leo asked dizzily, struggling to open his eyes although apparently not unconscious.

“Leo! You’re awake,” Donnie said in relief. “Quick, portal us out of here,” he instructed, thrusting Leo’s sword back into his hands, and fighting off the workers long enough for Leo to open a portal and get them out.

* * *

“You’ll be ok, nothing’s severely hurt,” Donnie stated, finishing up on Leo’s scan after they safely met up with Raph and Mikey and returned home.

“Cool, thanks…”

Donnie cleared his throat. “So I’m just gonna go to my lab and work on my battle shell. If anything gets worse let me know and I’ll have a look at it.”

“Right, will do.”

Donnie nodded and turned to leave.

“Wait- Don?”

“Mhm?”

“Ok, I’m pretty sure I was delirious during that fight… but did you call me your twin?” he asked hesitantly.

“ _What?"_ Donnie whipped around suddenly, feeling his heart rate pick up. "No- why would I call you- um...” he clamped his mouth shut. _What was he doing?? This was his chance to maybe fix things, and he was blowing it._

“Oh, ok… sorry, I thought I heard you say that.”

“Right… well, um-” Donnie tried to formulate a plan in his mind, or at least a few words to start with, but his mouth refused to open.

“-I’m sorry I said anything, I dunno why I thought you would say anything as stupid as that-”

“Leo, I-”

“I probably was delirious-”

_“Leo-”_

“I mean, why would you even want to be my brother, let alone my-”

“ _Leo I said it,"_ Donnie finally blurted out shakily. _"_ You weren’t delirious…”. 

“What?”

“I said it,” Donnie reconfirmed for emphasis, this time more firmly. “I called you my twin, alright?” he confessed, staring at the wall, at the floor, anywhere but where Leo was sitting. 

This felt too much like that night Leo had finally stopped calling him his twin.

“Why?” Leo asked flatly.

_Well. Not the response he was expecting._

_“Why?”_ Leo asked more firmly when he was met with silence.

“I… don’t know... “ Donnie finally answered, still unable to look him in the eye.

They stayed in silence for what felt like an eternity- Donnie standing near the doorway avoiding eye contact, and Leo remaining on his bed, waiting for something more.

Donnie sighed, cursing himself for not being able to speak as easily as he’d like. He always thought that if Leo found out, that he’d either be angry for denying it when they were younger only to accept it when it was convenient for him, or overly-enthused to the point where he would almost regret saying anything.

But this emotionless stare that he was receiving instead was far worse than any argument that could’ve ensued. But more than that, was what Leo just said… 

“Do you think I wouldn’t want you as a brother?” Donnie asked finally meeting his eyes while trying to keep his voice steady, dreading the answer that he might receive.

Leo shrugged in reply.

“You were always looking for excuses to say how we weren’t related… was I supposed to think that you were ok with being brothers?”

“Leo, I… I’m sorry.”

“What?”

“I’m sorry I made you feel like that,” he repeated, taking a step towards him. “I never meant it- well, I mean it _is_ true that there’s no logical way we could be twins, I did mean that- but that didn’t mean that I didn’t _want_ us to be… just I got kind of caught up in the whole ‘logistics’ of it and… I’m sorry,” he said again, unsure of what else to say since Leo didn’t seem to be reacting much to his words.

“Leo?”

“It's fine,” he responded quietly, which was a rare volume to hear Leo speak in. “I got over that whole… _thing_ when we were younger, it doesn’t bother me anymore.”

“It obviously does,” Donnie pointed out, taking another step forward. “And even if it doesn’t, I’m still sorry about what I said.”

Leo finally broke his emotionless stare and turned his head downwards instead. “Then why did you call me that? I thought we were just going to forget it ever happened.”

“I found an old photo of us that called us twins....” He admitted while feeling slightly stupid for having such a reason. “And I just- I guess I always wondered if we would’ve been closer if I stopped arguing with you about it… and the more I thought about it, the more the thought of having a twin seemed nice,” he finished awkwardly, unsure of what else to say. Leo’s face was still turned downwards, making it hard to figure out what he was feeling.

“So what? So you want us to ‘twins’ now?” Leo asked in what could have been either a mocking or defensive tone, causing Donnie to hesitate in his response- if he said ‘yes,’ then there was the chance Leo would tell him it was too late- but if he said ‘no,’ then that would be it. There’d never be a second- or actually, third- chance.

“Yeah,” he said softly. “If you do.”

Donnie left that offer hanging as they drifted off into silence for what felt like forever, making this conversation feel more like an incredibly long silence interrupted every so often by a few words. 

Instead of responding to Donnie’s offer though, Leo got up from his bed and slowly walked over where Donnie was standing and hugged him, tucking his face in between Donnie’s battleshell and neck. “Ok,” he replied as Donnie grasped what had happened and hugged him in return. “Let’s be twins.”

**Author's Note:**

> Thanks so much for reading!!
> 
> Sorry if they were OOC, I’m still trying to get the hang of writing the Rise characters <3
> 
> Tumblr: @overdramaticaly-dying


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